Śatapatha Brāhmaṇa ("of a hundred paths") 6.7.2.13

6.7.2.13

viṣṇoḥ kramo 'sīti | viṣṇurhi bhūtvā kramate sapatnaheti sapatnānhātra hanti gāyatraṃ canda āroheti gāyatraṃ canda ārohati pṛthivīmanu vikramasveti pṛthivīmanu vikramate praharati pādaṃ kramata ūrdhvamagnimudgṛhṇātyūrdhvo hi rohati

[Vâg. S. XII, 5] 'Thou art Vishnu's stride,'--for in the form of Vishnu he strides; 'the slayer of foes;'--for he now slays his foes;--'mount thou the Gâyatrî metre,'--the Gâyatrî metre he does mount,--'stride along the earth!'--along the earth he indeed strides. He stretches forward his (right) foot and strides: he raises the fire upwards, for upwards he ascends.